Numerical controller

Abstract

A path table operation is performed while updating the reference positions. When a read-out command in the path cycle table is read out, the reference positions are withdrawn and reset, and the respective axial positions at the time of the initiation of the path cycle command are stored. From the next period, the target positions are determined by adding the positions at the time of initiation to the respective axial positions corresponding to the reference positions stored in the path cycle table, and a path table operation is performed. A single path cycle table is sufficient for storing commands for portions to be repeatedly worked.

1. A numerical controller that is capable of driving respective axes by commanding respective axial positions with respect to reference positions in which time or spindle position is used as reference, as data in a tabular format, comprising:
 storage means that has a path table for storing respective axial positions with respect to the reference positions, and a path cycle table storing, as tabular format data, respective axial positions with respect to the reference positions, from a working start position to a working end position of the same working that is repeatedly performed; 
 first calculating means for calculating amounts of movement of the respective axes on the basis of said path table; 
 second calculating means for calculating the amounts of movement of the respective axes on the basis of the data in said path cycle table; and 
 driving means for adding the amounts of movement of the respective axes for operations calculated by said first and second calculating means and outputting the added amounts of movement to respective axial motors to perform driving the respective axes, 
 wherein the reference positions of the path table that stores the respective axial positions are data using time as a reference, and the reference positions of the path cycle table are data using positions on a spindle axis as a reference.